Gunnery teacher and time recorder



Nov. 30, 1926.

1,608,794 W. JEPSON GUNNERY TEACHER AND TIME RECORDER filed Feb. 2, 1.926 4 Sheets-Sheet 1 ME mwro Nov. 30 1926. 7 1,608,794

w. JEPSON GUNNERY TEACHER AND TIME RECORDER Filed Feb. 2, 1926 4 Sheets-Sheet 2 Nov. 30 1926. 1,608,794

- w. JEPSON GUNNERY TEACHER AND TIME RECORDER Filed Feb. 2. 1926 4 Sheets-Sheet 3 (C(mL.)

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ATTORNEY Nov. 30 1926. 1,608,794 W. JEPSON GUNNERY TEACHER AND TIME RECORDER Filed Feb. 2, 1926 4 Sheets-5heet 4 Patented Nov. 30, 1926.

WILLIAM JEPSOII, OF LONDON, ENGLAND.

GUNNERY TEACHER AND TIME RECOEDER.

Application filed February 2, 1926.

There has recently been developed an apparatus known as a gunnery teacher which is adapted to be mounted on the muzzle of a gun and carries a miniature tar get which the operator observes through the telescope, the target is given an irregular movement and the operator in bringing his line of sight on to the miniature representation for example of an enemy ship carried by the target moves the gun over as in actual firing compensating mechanism being provided whereby a corrective movement bring ing the target back to its zero position in its frame is automatically superimposed on the erratic movement received by the target, this correcting movement being proportional to the amount by which the gun is moved by the operator in endeavouring to bring the line of sight of his telescope back on to the sighting object.

The present invention has for its object to provide improvements in teachers of this kind. one of the principal objects being to provide a teacher in which safeguards are provided whereby over movement of the gun does not damage the apparatus.

A further object is to provide a pair of targets the gunner sighting on one target and an aiming ride or marker marking a second target, thus the target on which the gunner sights is not defaced in any way and he is not either helped or obstructed by marks made in connection with previous shots.

A further object of the invention is to anchor the cords by which the apparatus is connected to the ship to weights which lift so that excessive strain cannot be placed on said cords.

A further object is to provide a device for setting a predetermined time interval between successive shots since it is found in practice that the erratic movement given to the target may for a moment leave it in a fairly steady position, during which time the gunner can fire several shots more or less simultaneously which-would all be grouped closely together. The time on aim delay device, however, provides that between successive shots a definite interval of time must elapse which usually corresponds to the time normally taken to clear and reload the gun.

Other objects will appear in the following Serial No. 85,605.

description and be claimed in the appendant claims.

In the accompanying drawings Fig. 1 represents a view of the general arrangement Fig. 2 a rear elevation of a mechanism embodying the preferred form of the invention,

Figs. 3 to 8 show several small parts enlarged,

Fig. 9 illustrates the time on aim recorder and delay action device in sectional elevation.

Fig. 10 being a rear view on a smaller scale.

11 is a wiring diagram.

Referring now to Fig. 1, A represents a gun, B the teacher mounted thereon near the muzzle, C is a sighting telescope having a prismatic fitting attached to the objective so as to deflect the line of sight on to the teacher and D is an aiming rifle which may be an-air rifle adapted to project a missile into the bullet box E fitted behind the teacher A.

Referring now to Fig. 2, the teacher comprises a frame mounting in which is provided a target holder 1 which is free to move vertically in an outer frame 2 and to roll horizontally by means of a wheel 8 along the bar 3 of an L-shaped member 4:- The frame 2 is mounted by means of light parallel hinged arms 5 on a horizontal member of the frame 6 of the instructional apparatus, which is itself carried by the gun, being mounted thereon in any suitable manner, as for instance by a split collar and bolts as indicated in 1. The upright of the L-shaped member 4 is similarly mounted by light parallel hinged arms 7 on a vertical member of the frame 6. The arms 5 carry guide lugs 15 and the frame 1 lugs or flanges 10 so as to prevent the frames from swinging out of their appointed plane.

The target preferably consists of a card, and is loosely held in the holder 1 by overhanging flanges 11 and 12. A second target may be mounted in a second frame which is rigid with the holder 1. The sighting telescope C bears on the target in frame but the aiming rifle I) shoots through the card in holder 1 both as indicated in Fig. 1. Thus the operator of the gun is reouired to lUO aim at the representation of a ship or other object in frame and cannot defeat the object of the teacher by sighting on a hole or holes already made in the card by the aiming rifle. The target frame 1, 35 are given a to-and-fro irregular movement by means of a cord 13 anchored at the pin 14 and secured to the arm 9 which works in a slot in a giude plate 9 and is attached to the lower rail of the frame 1. The cord passes in the manner shown round two or more pulleys 16, each of which is eccentrcally mounted on a shaft adapted to be rotated by gearing driven from the motor 17. It will be seen that ac cording to the difference in phase and speed of rotation of the wheels 16. the cord 13 will give an irregular approximately horizontal movement to the frames 1. 35 drawing them towards the right in Fig. 1 and releasing them to return under the action. of a springcontrolled drum 9* secured by a cord 9 to a lug on frame 2, and that by altering the phase of the pulleys 1-5, the irregularities of the movement are capable of considerable variation. A similar cord 18, anchored at the pin 19 passes over two other eccentrically mounted pulleys indicated in dotted lines at 16 and gives to the L-shaped member 4 a corresponding irregular vertical movement. Both the horizontal component of the movement of the frame 2, and the vertical component of the movement of the L-piece are transmitted to the targets, which accordingly move in two planes in an irregular mannercapable of considerable variation according to the setting and relative speed of the wheels 16,. 16. It will be seen that both the horizontal and vertical components of the movement of the target are generally irregularly variable in speed and reversible in direction within the maximum amplitutude as distinct from being only regularly variable in speed after the manner of simple harmonic action.

Preferably, the pulleys producing th. horizontal"movement, and the pulleys for producing the vertical movement are mount ed at opposite ends of the same shafts. The shaft terminates at each end in a castellated socket 16 shown enlarged in Figs. 5 and 6-, and the pulley is eccentricallv mounted on a fitting adapted to enter the socket and be retained in a fixed position therein by the engagement of a projection 16. or projections in one or more of the notches in the socket rim. he fittings at each end are united y a light p 16d passing through the shaft, so that if it is desired to alter the phase of either pulley all that is necessary is to withdraw the fitting. and restore it collar capable of rotation relatively to the fitting. By this means I am able in a simple manner to effect a considerable variation in the primary curve of the independent un-' corrected movement of the targets, each variation differing both in horizontal and/or vertical amplitude and in general characteristics.

The movement arranged to be given to the targets by the wheels 16 is continuously corrected by an amount derived from and approximately proportional to the actual movement given to the gun by the gunners in following the target. T his is effected in the following manner which will be first described as regards training. A cord :20 is led more or less horizontally from the apparatus, over a pulley 36 and fixed to a Weight 37 Fig. 1, adapted to rest on the deck or on any other suitable support. The other end of the cord is secured toa spring wheel 21 in such a manner that as the gun recedes from or approaches the anchorage, the wheel. is caused to rotate either under the action of the cord or of its internal spring. The wheel is gearedwith a quadrant 22 which by means of apin 23. actuates the scissor arms 24; these in turn pull or release the pin i i to which the cord 13 is secured.

Assuming the targets to have been moved over to the left in Fig. 1. by the clockwork mechanism, the arrangement is such that as the muzzle end of the gun carrying the apparatus moves to the left under the operation of the gunner, the cord 20 revolves the wheel in a clockwise sense and causes. the quadrant and pin 1 to pull the cord 13, thus drawing the target back to the right and tending to restore it to the line of sight of the telescopes.

The quadrant gear is so constructed that the correcting movement imparted to the targets for a given movement of the gun can be adjusted to any suitable figure corresponding to the assumed range. The pin 14 is not fixed to the scissor arms but passes through a slot in a freely rotating plate, Fig. i, which is mounted on the axis 25 of the quadrant, and to which the pin 14 is adapted to be clamped nearer to or further away from the axis of rotation according as the range is supposed to be long or short. The scissor arms function as follows.

In the case illustrated, the pin 23 of the quadrant raises the upper arm, Fig. 3, depressing the tail piece 2% thereof, which through the intermediary of the spring 2% secured to the tail piece 24* of the other arm raises the latter and lifts the pin 1% which moves in the. same sense as the quadrant. Stops 26 are provided to limit the movement of the pin 14 so as to avoid risk of injury to the target frames in the event of the gunner moving the gun too far, the scissor arms providing an elastic link whereby overmanipulation of the gun only effects the opening of the scissor arms against the restraint of the spring 24. The mechanism for correcting the movement of the target in a vertical direction in connection with the elevation of the gim is similar to the above except that the operating cord 29 passes vertically downwards from the apparatus to the weight 38 to which it is anchored.

The pulley 21 as shown separately in Figs. 7 and 8 is mounted on a drum 40 and con nected thereto by means of an internal spring 41. One end facing of the pulley is provided with a lug 42 adapted to be en gaged by an arm 43 mounted co-aXially with the pulley and drum but capable of separate movement. A pin 44 is mounted on the drum also adapted to be engaged by the arm 43. The projecting shaft 45 of the pulley has a toothed end to receive the spur wheel 46 engaging with the quadrant 22. Assuming the pulley to be rotatable in a clockwise direction in Fig. 7 it will be seen that the lug 42 first makes almost a whole revolution and then engages the arm 43 which it carries round. After a second revolution of the pulley the arm 43 abuts against the pin 44 which as indicated in Fig. 2 abuts against an arm of the frame 6 of the teacher. Thus further rotation of the pulley is prevented and if the gun carrying the teacher is moved further over to the left in Fig. 2 the cord 20 raises the weight 37 from the deck and the correcting mechanism ceases to function. This presents the advantage firstly that the quadrant 22 is not rotated clean off the wheel 46, in which case the exact setting might be lost when it was put back, and secondly the arrangement of the weight 37 limits the strain put on the cords 20 and 13 so that the apparatus is not liable to be damaged by an. unexperienced gunner.

If desired, a dotter and liner mechanism may be used instead of the aiming rifle, this being of known construction and comprising two pencil holders 27, 28 adapted to be so set that in the case of the former, the pencil dots the back of the upper target on the trigger being pressed by the gunner for a shot, electrical connections for this purpose being shown at 32, and in the case of the liner, the pencil can by means of the cord 33 be set in engage ment with the back of the target throughout the shoot, when it traces the following curve.

As described, the amount by which the target is corrected will not in all positions be in mathematically exact proportion to the movement of the gun; but it will be understood that by limiting the movement of the frame and L-piece to a small arc, and by having long leads to the ouadrant-actuating cords, the amount of the deviation from exact proportion will be negligible for educational purposes. Fittings may if necessary be provided for making the leans more nearly horizontal and vertical, but it will usually be found that existing parts of the ship or station can be so adapted.

In cases where the gun-sighting mechanism is so constructed that both the elevating and training telescopes cannot at one and the same time be brought to bear upon one target carried by the gun, I may arrange to have two targets set athwart the gun, both receiving identical motion from a clockwork or other cam pulley mechanism as described,but one target receivin all the readings, and the other merely serving for sighting. The amount of movement of the target arising from the correction factor may be varied by having various sized plates of the kind shown in Fig. 4, some variation being desirable in order when the rifle is used that the shots should not be grouped too closely together. This I prefer to accomplish by the provision of double pulleys near the anchorage of the cords, the operating cord being in each case secured to the smaller pulley, and the larger pulley, which rotates with the smaller one, actuating a second cord which moves with the smaller one, actuating a second cord which moves the targets.

Turning now to the time on aim recorder shown more particularly in Fig. 9, this comprises a clockwork train driven from a spring drum 50 and controlled by a centrifugal governor 51. The train ultimately rotates a wheel. 52 carrying a single pin 53 which gives a stepby-step motion in a counter-clockwise sense in Fig. 9 to a quadrant 54 pivoted at 55 and engaged by a pawl 56 which prevents it from falling back under gravity. The quadrant carries a stud 57 adapted at the end of its lift to make conact between a pair of spring strips 58 in series with the main operating circuit. The pawl 56 is carried by a spring-controlled armature 59 adapted to be moved to the right in Fig. 9 on the energizing of solenoid 60. The zero position to which the quadrant can fall is set by a pin 61 on a quadrant 62 adapted to be setat the required position by a needle 63, Fig. 2, and it will be realized that according to the setting of quadrant 62 the zero position of quadrant 54 will be varied. The obverse of the recorder is fitted with a drum 64 feeding forward a tape 65 at constant speed, the tape being engaged by a pencil 66 carried by an arm 67 mounted on a sliding rod 68 of which one end is fitted with a conical head 69, Fig. 9, the head 69 being engaged by a strip 70 carried by the armature 59.

The wiring diagram, Fig. 11, includes a battery 7], switch 72 operated by the firing mechanism, a solenoid 60 already referred to, strips 58 already described, and coil 73 operating either the aiming rifle or the dotter mechanism described above.

It will thus be seen from Figs. 9 and 11 that on each operation of the firing mechanism the armature 59 is attracted to the solenoid and the pawl 56 disengages from the quadrant 54. which falls back to the zero position set by quadrant 62. Before another shot can be fired it is necessary for the quadrant to be raised again by the pin 53 so that the stud 5'? re-engages the strips 58. Assuming that the pin 53 rotates for example once per second, it will be appreciated that by setting the quadrant 62 in any suitable position up to 20 seconds indicated on the front of the recorder in Fig. 2, that period of time will be required to elapse after each shot before another shot can be fired. It will be understood that the setting back of the pawl 56 is only momentary since the current in the solenoid 60 is broken as soon as the stud 57 moves away from the strips 58. Giving to the conical shape of head 69 the setting back of the armature 59 causes the shaftGS carrying pencil 66 to make a transverse movement across the face of the tape and so the time between successive shots is permanently recorded. Just before making contact with the strips 58 the stud 57 presses a spring-controlled lug T5 and causes a clapper 76 to strike a bell 7'? to give an audible signal indicating that the time has elapsed and the mechanism, is ready for a further shot.

The front face of the recorder is fitted with a winding key 80 and a dial 81 which may be a five minute dial to facilitate five minute tests for separate gunners and a dial 82 which'maybe a minute dial so that the officer in charge can see how quickly the operator is performing his exercises.

Preferably, the recorder is mounted on the side of the teacher by means of an angle bracket 90 as shown in Fig. 2, but it may if desiredbe self-contained in a separate unit.

I claim 1. In apparatus for practising gunnery, a frame, means for mounting said frame rigidly with a gun, a target movable in said frame, means for imparting to said target an erratic movement relatively to said frame, a plurality of flexible connectors extending from said. target in a plurality of directions, means whereby movement of said gun causes said connectors to superimpose a correcting movement on the said erratic movement of said target, and means to limit the: tension on said connectors.

2. In apparatus for practising gunnery, a frame, means for mounting said frame rigidly with a gun, a target movable in said frame, means for imparting to said target an erratic movement relatively to said frame, a plurality of flexible connectors ex tending from said target in a plurality of directions, pulleys to said frame, said connectors passing over said pulleys, means whereby movement of said gun causes said connectors to rotate said pulleys, means whereby said rotation superimposes a correcting movement on the said erratic movement of said target, and means to limit the rotation of said pulleys.

which the means to limit the rotation of said pulleys comprises a lug on said pulley,

impose a correcting movement on the said erratic movement of said target, and means to limit the tension on said connectors said means comprising weights suspended there from.

5. In apparatus for practising gunner a frame, means for mounting said frame rigidly with a gun, a target movable in said frame, means for imparting to said target an erratic movement relatively to said f'ame, firing mechanism to said gun, a marker adapted to coact with said target, means to cause said marker to mark said target when said firing mechanism is operated, means to render said marking means inoperable from said firing mechanism for a predetermined time after each operation.

6. Means as claimed in claim 5 in which said predetermined time can be varied.

7. In apparatus for practising gunnery, a gun, firing mchanism to said gun, a target, a marker adapted to marl: said target, an electrical circuit connected to said firing mechanism and to said marker, a breaking point in said circuit, automatic means to open said circuit at said point when said firing mechanism is operated, and automatic means to close said circuit at said point after a predetermined interval of time thereafter. 7

8. Means as claimed in claim 7 in which said interval can be varied.

9. In apparatus for teaching and practising gunnery, a time on aim recorder comprising a moving band, a marker coacting therewith, and'means causing said marker to move transversely over said band at every shot.

10. In apparatus for practising gunnery, a firing mechanism, a target, a marker to said target, anelectrical circuit, a break in said circuit, a clockwork train, means given a regular movement from a zero position by said train and adapted when moved to a certain point to close said circuit at said 0. The combination claimed in claim 2 in break, means whereby when said break is closed and said firing mechanism is oper ated, said regularly moved means is moved back to its zero position and re-opens said circuit at said break.

11. In apparatus for practising gunnery, a firing mechanism, a target, a marker to said target, an electrical circuit, a break in said circuit, a clockwork train, means given a step-by-step movement from a zero position by said train and adapted when moved to a certain point to close said circuit at said break, means whereby when said break is closed and said firing mechanism is operated, said intermittently moved means is moved back to its zero position and re-opens said circuit at said'break.

12. In apparatus for practising gunnery, a firing mechanism, a target, a marker to said target, an electrical circuit, a break in said circuit, a clockwork train, a zoothed sector, a pin carried by a crank rotated by said train and adapted to move said sector in a positive direction from a zero position by one tooth at each revolution of said crank, means carried by said sector to close said circuit at said break when moved to a certain point, means urging said sector in the reverse direction and an electrically-0on trolled catch normally preventing said reverse movement, a coil controlling said catch said coil marker and firing mechanism being connected to said electric circuit, and means whereby when said circuit is closed,

and said firing mechanism is operated, said catch is withdrawn from said sector and said sector thereupon moves back to its zero position.

13. Means as claimed in claim 12 including an abutment against which said sector is moved and which thereby determines its zero position, and means for setting the position of said abutment.

14. Means as claimed in claim 12 including a regularly moved band, a marker adapted to coact therewith, and means to operate said marker at each operation of said firing mechanism occurring when said current is closed.

15. Apparatus as claimed eluding means to give an when said circuit is closed.

16. Apparatus as claimed eluding means to give an when said circuit is closed.

17. In apparatus for practising gunnery, a gun, a miniature target mounted thereon, means to give said miniature target an erratic movement, .a second target movable with said miniature target, means for sight ing on said miniature target, firing mechanism to said gun, and means to project a missile to said second target when said firing mechanism is operated.

In testimony whereof I afiix my signature.

in claim 10 inaudlble signal in claim 12 inaudible signal WILLIAM J EPSON. 

